Pairs of crown gear toothings consist of a smaller straight-toothed gear having teeth with axis-parallel mantle lines, i.e. with a straight spur gear toothing, for example an involute toothing, and of a larger ring-gear-like crown gear. The latter has a type of toothing which is obtained when rolling on the smaller straight-toothed gear when the gears are mounted in such a way that their axes extend perpendicularly relative to one another. Extending perpendicularly in this sense means intersecting at right angles or distal crossing at right angles for the axes. The toothing flanks of the crown gear comprise mantle lines which extend substantially radially relative to the axis of the crown gear. Mantle lines in this case refer to tooth engagement lines and tooth contact lines.
In contrast to bevel gear drives or cycloid drives which are frequently used for transmitting torque between shafts whose axes extend perpendicularly relative to one another, crown gear toothings are advantageous in that they are relatively insensitive to setting errors. In particular, the axial setting of the pinion can be relatively inaccurate because, when the axial setting of the pinion is changed within certain limits, the tooth engagement does not change in any way. Nevertheless, the pinion always has to be axially secured relative to the crown gear.